Neurology - Botox treatment for Chronic Migraine

This information leaflet discusses the use of Botox® for the treatment of chronic migraine at Salford Royal Hospital.

Botulinum Toxin Type A (known as Botox®) was approved by the National Institute for Health and Care Excellence (NICE) in June 2012 for the treatment of chronic migraine in selected adults.

What is Botox®?

Botox® is a toxin produced by a bacterium called Clostridium Botulinum. It blocks nerve endings and can cause muscle weakness and block pain signals.

Botox® was first introduced in medical practice in the 1970s to treat squints. Since then, it has found uses in other areas of medicine including in the treatment of chronic migraine.

Botox® and headache

In the mid-1990s a number of people who were receiving Botox® for cosmetic reasons reported improvement in their migraine.
Clinical trials of Botox® in migraine followed.

What is chronic migraine?

This is a headache disorder in which there are at least 15 days of headache each month. A minimum of 8 of these must be typical for migraine-type headaches.

Migraine headaches are often associated with sensitivity to light, sound and movement, nausea and are throbbing in nature.

What is the evidence that Botox® can help with chronic migraine?

Two large trials (PREEMPT trials) recruited 1384 patients with chronic migraine. These patients were selected at random and treated with either Botox® or a placebo (injections of saline, salty water).

These patients were suffering on average 20 days of headache each month, of which 18 were moderate to severe. Those treated with Botox® received 31 injections into specific sites in the scalp and neck every 12 weeks over 56 weeks. After 12 months, 70% of those treated with Botox® had less than half of the number of headaches.

The placebo group saw a 30% response to the injections, compared with a 40% response from the Botox® giving a difference of 1.8 fewer headache days per month in the Botox® group.

How do we decide whether Botox® is appropriate?

The criteria to receive Botox® are:

• Have a diagnosis of chronic migraine
• 3 different migraine preventative medications haven’t worked, when taken for at least 3 months at maximum tolerated target doses. Alternatively, they are unsuitable because of safety concerns or not tolerated
• Any analgesic or triptan overuse has been managed appropriately
• A headache diary has been completed for at least one month before the start of Botox® treatment
• If your migraine does not respond after 2 courses of Botox®, the treatment will be stopped
• If it is effective, treatment is usually continued for 1 year and then reviewed

How does Botox® help treat chronic migraine?

How Botox® works in chronic migraine is not fully understood.

It is thought that it may reduce the transmission of pain messages to the brain. This may reduce over-activity in the part of the brain which generates migraine.

What does the treatment involve?

The treatment involves 31-39 injections of Botox® into the muscles around the head, neck and shoulders.

These injections are repeated every twelve weeks.

Although licensed as a single-use vial, current practice within Northern Care Alliance, and many other neuroscience centres, is for multiple use of single vials within one clinic. This helps prevent waste of an expensive drug. This is similar to the way some vaccines are used and has been standard practice for decades without any issues. As this is considered an ‘off license’ use, this will be included on the consent form. If you have any questions about it, you can discuss with your headache practitioner.

Are there any side effects?

The commonest side effects are:

• Neck pain (6.7%)
• Temporary worsening of headaches
• Reduced forehead muscle movement
• Drooping of an eyelid (3.3%)

No serious irreversible side effects have been reported in trials of Botox® in headache.

The bottle of botulinum toxin also contains a tiny amount of human albumin. This is a protein extracted from blood donations. There is a theoretical risk of spreading viral or other infectious germs from the blood of the donors, but it is screened for that.

The injections themselves are not too painful to receive and feel like a sharp needle prick.

If you are taking any blood thinning medication (anticoagulants) please let your clinician know as special precautions may need to be undertaken.

These include:

• Warfarin
• Dabigatran
• Apixaban
• Rivaroxaban

Pregnancy and breastfeeding

Botox is not licensed for use during pregnancy and should be avoided if possible. Migraine sometimes improves spontaneously during pregnancy. The risks of Botox treatment during pregnancy and breast feeding should be discussed with your clinician.

What to do after treatment?

A headache diary will need to be completed to record the number and severity of headaches/migraine occurring after the injections. Without these diaries, we cannot provide treatment.

Rubbing the injection sites and hair washing should be avoided for the first 24 hours.

To avoid a massage of the head, neck and shoulders for 2 weeks. You can travel home on your own after treatment.

Who might benefit from Botox® for chronic migraine?

Only patients with chronic migraine may benefit from treatment. The research shows that episodic migraine (fewer than 15 headache days per month) does not improve with Botox®.

There are other treatments available to patients with chronic migraine. It is important that patients discuss their headaches and options for treatment with a practitioner experienced in the diagnosis and management of headaches before a decision to use Botox® is taken.

Contact details and further advice

The Headache Team - Salford Royal Hospital
Telephone 0161 206 2563 / 0161 206 5507

Useful websites

www.migrainetrust.org
www.migraine.org.uk
http://www.nice.org.uk/guidance/ta260/chapter/1-guidance
(National Institute of Health and Care Excellence Guidance TA260)